Genesis 11:7
5 But the Lord came down to see the city and the tower that the people had started building. 6 And the Lord said, “If as one people all sharing a common language they have begun to do this, then nothing they plan to do will be beyond them. 7 Come, let’s go down and confuse their language so they won’t be able to understand each other.” 8 So the Lord scattered them from there across the face of the entire earth, and they stopped building the city. 9 That is why its name was called Babel—because there the Lord confused the language of the entire world, and from there the Lord scattered them across the face of the entire earth.
Pseudo Jonathan Genesis 11:9
6 And the Lord said: 'Behold they are one people, and they have all one language, and they have planned to do this! And now, nothing they plan to do can be withheld from them.' 7 Then the Lord said to the seventy angels that stand before him: 'Come then, let us go down, and confuse their language there, so that they will not understand one another’s language.' 8 The Memra of the Lord was revealed against the city; and with it seventy angels corresponding to seventy nations, each having the language of his people and the characters of its writing in his hand. He scattered them thence upon the face of all the earth into seventy languages, so that one did not know what the other said, and they killed one another. And they stopped building the city. 9 That is why it was called Babel, because there the Lord confused the language of all the inhabitants of the earth; and from there the Lord scattered them upon the face of the whole earth.
Notes and References
"... When the LORD descended to the Tower of Babel (Genesis 11:1-19), he took with him the seventy angels who perpetually stood before him. And at the Tower, he divided humankind into seventy languages and nations, one for each of the seventy angels and then dispersed humankind over the face of the earth, having appointed one of the seventy angels as their guardian. The guardianship of Israel, however, he kept as his own responsibility. The last detail either takes place immediately at Babel or later at Sinai. This legend, which we will term the Angelic Patron Legend, appears in Targum Pseudo-Jonathan at Genesis 11:7-8 and at Deuteronomy 32:8-9, in the Hebrew Testament of Naphtali 8:4-10:2, and in Pirqe de Rabbi Eliezer 24, none of which can claim to be earlier than medieval times. Nonetheless, it is plausible to suppose that the legend itself is much earlier. In fact, a case can be made that it was already presumed by the author of Jubilees. Two different passages suggest this. First, in its retelling of the Tower of Babel story (Jubilees 10:22-23), God took the angels with him when he descended to see the Tower, but no mention is made of the number of angels, nor of the seventy languages ..."
Hannah, Darrell, D. Guardian Angels and Angelic National Patrons in Second Temple Judaism and Early Christianity (pp. 413-435) De Gruyter, 2007